710 



MAMMALIA 



[CH. 



The ANTHROPOIDEA, including the true Monkeys and Man, are 

 distinguished by the fact that the bony ring surrounding the orbit 

 sends inwards a plate of bone, which completely separates the orbit 

 from the temporal fossa. Further, the cerebral hemispheres conceal 

 the cerebellum when the brain is viewed from above ; the placenta 

 is at first spread all over the surface of the egg but later becomes 

 highly developed and concentrated on one part of the wall of the 



FIG. 359. The Eing-tailed Lemur, Lemur catta. 



uterus, and there are never more than two mammae. This sub- 

 order of Primates is divided into five families, viz., HAPALIDAE, 

 CEBIDAE, CERCOPITHECIDAE, SIMIIDAE, and HOMINIDAE, the last being 

 constituted of the single species, Homo sapiens, Man. 



The HAPALIDAE and CEBIDAE are confined to South and Central 

 America, and are sometimes grouped together as PLATYRRHINI 

 (Gr. TrAarvs, broad ; pi's, pu/o?, nose). The animals belonging to this 



